Spatial multizone soundfield reproduction over an extended region of space has recently drawn increased attention due to its various applications such as simultaneous car entertainment systems, surround sound systems in exhibition centers, personal loudspeaker systems in shared office space, and quiet zones in a noisy environment, where the aim is to provide listeners an individual sound environment without having to use acoustical barriers or headphones. Generally, a soundfield can be considered to describe the deviations of the local air pressure from the ambient pressure, i.e. the pressure variations, as a function of space and time caused for instance by the sound signals emitted by a plurality of loudspeakers. A multizone soundfield usually can comprise one or more acoustically bright zones and possibly several acoustically quiet zones.
A so-called “non-robustness” problem of multizone sound reproduction was identified in Poletti, M., “An investigation of 2D multizone surround sound system,” Proc. AES 125th Convention Audio Eng. Society, 2008 in the form of a very obvious redundant sound between two selected regions with an amplitude even greater than the sound in the acoustically bright zone. In practice, such a behavior in a multizone soundfield can lead to unpleasant user experiences within these areas.
Thus, there is a need for improved apparatuses and methods for processing soundfield data addressing, in particular, the “non-robustness” problem described above.